- Joined: 11 Jan 2006
- Posts: 29
- Location: Midlands, UK
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SN76489 In Visual Basic
 Posted: Tue Sep 08, 2009 7:14 pm
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Hi, I think vbt originally ported the SN76489 emulation from the Gens project to Visual Basic for use in olafs vbsms.
See in the port there are some problems with the psg noise generator and the Psg.Counter values for every channel, in the vb module the values always overflow in the psg_update sub. Now I've rewritten the code from C to vb and I keep getting the same problems, does anyone know whats going on;
Can anyone help fix this??
Below are the source of an old vbsms project and the psg.c source files.
any help appreciated.
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- Site Admin
- Joined: 19 Oct 1999
- Posts: 14745
- Location: London
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Posted: Wed Sep 09, 2009 11:46 am
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It looks like these counters are deliberately overflowing. If that is a problem for the VB version then you can try to rewrite it to avoid it, or maybe try converting a simpler implementation. (My one is complicated by interpolation.)
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olafguest
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Posted: Thu Sep 10, 2009 6:01 am
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brom wrote Hi, I think vbt originally ported the SN76489 emulation from the Gens project to Visual Basic for use in olafs vbsms.
It was from his port of SMS Plus to the Sega Saturn, IIRC.
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- Joined: 29 Jun 1999
- Posts: 254
- Location: California, USA; Hiroshima, Japan
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Posted: Mon Sep 14, 2009 3:17 am
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Which version of VB are you using? I just finished my own SN76489 core using Visual Basic 2008. It sounds great, if I do say so myself. :) I'd be glad to send you the source.
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olafguest
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Posted: Tue Sep 15, 2009 2:21 am
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